University of South Bohemia, Faculty of Science, Department of Zoology, Branišovská 31, 370 05 České Budějovice, Czech Republic.
Mol Phylogenet Evol. 2012 Jan;62(1):46-61. doi: 10.1016/j.ympev.2011.09.006. Epub 2011 Sep 25.
First multilocus analysis of the largest Neotropical cichlid genus Crenicichla combining mitochondrial (cytb, ND2, 16S) and nuclear (S7 intron 1) genes and comprising 602 sequences of 169 specimens yields a robust phylogenetic hypothesis. The best marker in the combined analysis is the ND2 gene which contributes throughout the whole range of hierarchical levels in the tree and shows weak effects of saturation at the 3rd codon position. The 16S locus exerts almost no influence on the inferred phylogeny. The nuclear S7 intron 1 resolves mainly deeper nodes. Crenicichla is split into two main clades: (1) Teleocichla, the Crenicichla wallacii group, and the Crenicichla lugubris-Crenicichla saxatilis groups ("the TWLuS clade"); (2) the Crenicichla reticulata group and the Crenicichla lacustris group-Crenicichla macrophthalma ("the RMLa clade"). Our study confirms the monophyly of the C. lacustris species group with very high support. The biogeographic reconstruction of the C. lacustris group using dispersal-vicariance analysis underlines the importance of ancient barriers between the middle and upper Paraná River (the Guaíra Falls) and between the middle and upper Uruguay River (the Moconá Falls). Our phylogeny recovers two endemic species flocks within the C. lacustris group, the Crenicichla missioneira species flock and the herein discovered Crenicichla mandelburgeri species flock from the Uruguay and Paraná/Iguazú Rivers, respectively. We discuss putative sympatric diversification of trophic traits (morphology of jaws and lips, dentition) and propose these species flocks as models for studying sympatric speciation in complex riverine systems. The possible role of hybridization as a mechanism of speciation is mentioned with a recorded example (Crenicichla scottii).
首次对包括线粒体（细胞色素 b、ND2、16S）和核（S7 内含子 1）基因在内的最大的新热带慈鲷属 Crenicichla 进行多基因座分析，共包括 169 个样本的 602 个序列，得到了一个稳健的系统发育假说。在联合分析中，最好的标记是 ND2 基因，它在树的整个层次结构范围内都有贡献，并且在第三密码子位置显示出较弱的饱和效应。16S 基因座对推断的系统发育几乎没有影响。核 S7 内含子 1 主要解决更深的节点。Crenicichla 分为两个主要分支：（1）Teleocichla、Crenicichla wallacii 组和 Crenicichla lugubris-Crenicichla saxatilis 组（“TWLuS 分支”）；（2）Crenicichla reticulata 组和 Crenicichla lacustris 组-Crenicichla macrophthalma（“RMLa 分支”）。我们的研究证实了 C. lacustris 物种组的单系性，支持率非常高。使用扩散变异分析对 C. lacustris 组的生物地理重建强调了中上游巴拉那河（瓜伊拉瀑布）和中上游乌拉圭河（莫科纳瀑布）之间古老屏障的重要性。我们的系统发育恢复了 C. lacustris 组内的两个特有种群，即 Crenicichla missioneira 种群和此处发现的来自乌拉圭河和巴拉那河/伊瓜苏河的 Crenicichla mandelburgeri 种群。我们讨论了可能的共生营养特征（下颚和嘴唇的形态、牙齿）的趋同进化，并提出这些种群作为研究复杂河流系统中同域物种形成的模型。提到了杂交作为一种物种形成机制的可能作用，并记录了一个例子（Crenicichla scottii）。
